JRC scientists investigate toxicity of gold nanoparticles
Analysis of uptake and intracellular distribution
|Contact Name||JRC-IHCP, Nanotechnology|
Gold nanoparticles (AuNPs) are currently used in several fields, including biomedical applications, although no conclusive information on their cytotoxicity is available. The aim of this study, by a team of scientists of the European Commission Joint Research Centre, Institute for Health and Consumer Protection, was to provide additional data on the toxic potential exerted by AuNPs.
The effects of AuNPs of two different sizes (5 and 15 nm) were investigated on an in vitro model (the Balb/3T3 mouse fibroblast cell line) previously used to assess concurrent cytotoxicity and morphological transformation of nanomaterials. The sensitivity of this cell model and the reliability and reproducibility of the assay used in this test (Colony Forming Efficiency assay) makes it a valuable tool to screen nanoparticles toxicity. In addition, in order to unveil differences among the two types of AuNPs, the uptake mechanisms of AuNPs in Balb/3T3 and the modification of the cellular cytoskeleton have been investigated.
The study highlighted that cytotoxicity results can be better understood and more correctly interpreted when combined with cell interaction studies by TEM (Transmission Electron Microscopy) and ICP-MS (Inductively Coupled Plasma - Mass Spectrometry) techniques. The TEM analysis showed that NPs are entering into the cells where they are confined in vesicles without reaching the nucleus. The AuNPs uptake was also quantified by ICP-MS, revealing that the total Au content in cells increased in a time-dependent manner without reaching a plateau in the first 24 h. AuNPs were shown to damage the cytoskeleton organization, with the most prominent effect seen for AuNPs 5 nm.
The overall biological response of AuNPs of 5 and 15 nm is significantly different. It would be interesting to identify, from the mechanistic point of view, how AuNPs of different sizes affects cells biology.
Read the full article:
"Size-dependent toxicity and cell interaction mechanisms of gold nanoparticles on mouse fibroblasts", by R. Coradeghini, S. Gioria, C. P. García, P. Nativo, F. Franchini, D. Gilliland, J. Ponti, F. Rossi, in 'Toxicology Letters' (available online 13 December 2012); doi:10.1016/j.toxlet.2012.11.022
Photo: TEM image of Balb/3T3 cell exposed to AuNPs showing NPs entering into the cell. Copyright EU 2012.